We got some users that don't want other users to see which group they belong to. So I was thinking, if it was possible to change the owner group to "NoGroup" or "Siteops".
I would think that would cause some problems with things like chmod, but what do I know :S
So is it possible to change the owner group to something else?
It is possible to just change the owner of group/files. Use "site chown :groupname file/dir" which will just change the group. With v6 you can use -R to recursively do that, and to specify wildcards. Check the ChangeLog for details. By default a user requires the V flag to use chown which is not something you want to give out normally to users.
Changing the default group for everyone so the are in the same group won't matter at all unless you are using groups for credits or something with a script. You can certainly be a member of more than one group, but I think most scripts assume the first group is "your group" just like the filesystem does.
Not sure what script add-ons you are using, but I'd just go with the simple default group change if people are really interested in hiding their group.
Since users can be members of more than one group, just like Yil says, a simple solution could be to put all users in a generic main group called "users" or something like that (as first group). I think that will show up as group owner. Then add them to that secret group name so that they don't lose any special group permissions. Should work.
We did this before on some sites. What place are you asking about? in irc? Or in the FTP site?
If it is IRC, that is a very easy one. Just modifi the announce script where it says something like %bold%user%bold@%group and rename it to %bold%user%bold@PROTECTED or something
then it would say like JACK@PROTECTED....
It will look like everyone is in the same grp in IRC, but behind the scenes, everythign stays the same.